The Central Processing Unit

Processor and Main Memory

Learning Intentions• We are learning to:• State the function of the processor• Describe the differences between RAM and

ROM• Make comparisons between computer systems

using processor speed and main memory size.• State the function of graphics and sound cards.

The Computer System

INPUT OUTPUT

BACKING

STORAGE

Processor

MAIN MEMORY

Processor and Main Memory

• Processor - Deals with all the movement of data and the calculations that need to be carried out.

• Main Memory-Used to store programs and data

Processor

Main Memory

Makes of processor

Clock speedA5 processor (IPAD)

Intel Core i7

• Clock speeds are a measure of how powerful a processor is.

• 1 Megahertz (1 MHz) = 1 million pulses per second

• 1 Gigahertz (1 GHz) = 1000 million pulses per second

800MHz

3.2 GHz

Clock speed examples

Type System Processor Speed

Smartphone BlackBerry Bold 9780

624 MHz Slowest

Tablet Samsung Galaxy Tablet 2

1 GHz

Laptop Asus Ultrabook 1.6 GHz

Desktop HP Desktop PC 3.4 GHz Fastest

The Main Memory

• The main memory can be either RAM or ROM.

• Random Access Memory is the working space of the computer.

• It holds all the programs and data you are currently using.

• When you are using MS Word it has been loaded from your computer’s hard disk into RAM.

• The unsaved work you have typed so far is also held in RAM.

Read Only Memory

• Read Only Memory is used by the computer to store data permanently.

• In computer systems ROM is used to store the Operating System of your computer.

• Stores the programs that run MP3 players, Washing machines, Central Heating system and other devices in your home

• It is very difficult to change the data held in ROM

RAM vs ROM

Random Access Memory Read Only Memory

Read and Write Read Only

Data can be changed Data CANNOT be changed

Data is lost when power is switched off - Temporary

Data is kept when power is switched off - Permanent

Holds all the data and programs currently in use

Holds instructions the computer and devices need to carry out their function

Complete the table in your jotterComputer

SystemProcessor Speed Main Memory

(RAM)Samsung Galaxy S smartphone

1 GHz 512 Mb

Yarvik Zania 10 TabletAcer Apsire UltrabookASUS Essentio Desktop PC

Using www.pcworld.co.uk

AnswersComputer

SystemProcessor Speed Main Memory

(RAM)Samsung Galaxy S smartphone

1 GHz 512 Mb

Yarvik Zania 10 Tablet

1.2 GHz 1 Gb

Acer Apsire Ultrabook

1.7 GHz 4 Gb

ASUS Essentio Desktop PC

3.3 GHz 4 Gb

Graphics Card• Specialised piece of

hardware used to process the images and videos you see on your screen.

• They have their own processor and memory.

• The CPU then has the time to get on with processing other data.

• The best graphics cards allow your games to run smoothly.

Graphics Card- In Your JotterGraphics Card Processor

speed (frequency)

Memory Price

PNY Ge Force 8400

ASUS AMD Radeon HD6770 ASUS NVIDIA Geforce GTX 680 Using www.pcworld.co.uk

AnswersGraphics Card Processor

speed (frequency)

Memory Price

PNY Ge Force 8400

520 MHz 512 Mb £ 19.97

ASUS AMD Radeon HD6770

850 MHz 1 Gb £99.99

ASUS NVIDIA Geforce GTX 680

1201 MHz 2048 Mb (2Gb)

£468.00

Sound Cards

• The sound card is used to capture and output audio data.

• They improve the quality of sound output from games and multimedia.

• Sample Rate: A measure of the quality of the sound that has been captured. Measure in KHz

Sound Card shopping- In your jotter

Graphics Card Test Frequency(Sample Rate)

Price

CREATIVE Sound Blaster X-Fi Xtreme ASUS Xonar HDAV1.3

Using www.pcworld.co.uk

Answers

Graphics Card Test Frequency(Sample Rate)

Price

CREATIVE Sound Blaster X-Fi Xtreme

Up to 96 kHz £39.97

ASUS Xonar HDAV1.3

192 kHz £129.97